Crohn's disease (CD) results from a complex interplay between host genetic factors and endogenous microbial communities. In the current study, we used Ion Torrent sequencing to characterize the gut ...bacterial microbiota (bacteriome) and fungal community (mycobiome) in patients with CD and their nondiseased first-degree relatives (NCDR) in 9 familial clusters living in northern France-Belgium and in healthy individuals from 4 families living in the same area (non-CD unrelated NCDU). Principal component, diversity, and abundance analyses were conducted, and CD-associated inter- and intrakingdom microbial correlations were determined. Significant microbial interactions were identified and validated using single- and mixed-species biofilms. CD and NCDR groups clustered together in the mycobiome but not in the bacteriome. Microbiotas of familial (CD and NCDR) samples were distinct from those of nonfamilial (NCDU) samples. The abundance of Serratia marcescens and Escherichia coli was elevated in CD patients, while that of beneficial bacteria was decreased. The abundance of the fungus Candida tropicalis was significantly higher in CD than in NCDR (P = 0.003) samples and positively correlated with levels of anti-Saccharomyces cerevisiae antibodies (ASCA). The abundance of C. tropicalis was positively correlated with S. marcescens and E. coli, suggesting that these organisms interact in the gut. The mass and thickness of triple-species (C. tropicalis plus S. marcescens plus E. coli) biofilm were significantly greater than those of single- and double-species biofilms. C. tropicalis biofilms comprised blastospores, while double- and triple-species biofilms were enriched in hyphae. S. marcescens used fimbriae to coaggregate or attach with C. tropicalis/E. coli, while E. coli was closely apposed with C. tropicalis Specific interkingdom microbial interactions may be key determinants in CD.
Here, we characterized the gut bacterial microbiota (bacteriome) and fungal community (mycobiome) in multiplex families with CD and healthy relatives and defined the microbial interactions leading to dysbiosis in CD. We identified fungal (Candida tropicalis) and bacterial (Serratia marcescens and Escherichia coli) species that are associated with CD dysbiosis. Additionally, we found that the level of anti-Saccharomyces cerevisiae antibodies (ASCA; a known CD biomarker) was associated with the abundance of C. tropicalis We also identified positive interkingdom correlations between C. tropicalis, E. coli, and S. marcescens in CD patients and validated these correlations using in vitro biofilms. These results provide insight into the roles of bacteria and fungi in CD and may lead to the development of novel treatment approaches and diagnostic assays.
Introduction Les ostéites à Staphylococcus aureus sont une complication fréquente (10 à 60 %) et grave des plaies du pied chez le diabétique. Le but de cette étude était d’évaluer les clones de S. ...aureus circulants en France dans cette pathologie. Patients et méthodes 57 patients diabétiques (63 % d’hommes, âge médian 67 ans), ayant une ostéite du pied ont été inclus du 1/01/08 au 31/12/10 dans 12 CHU en France. Après préparation de la plaie, un prélèvement était réalisé par biopsie osseuse. Les prélèvements monomicrobiens à S. aureus étaient conservés pour étude génotypique par biopuces à ADN (StaphyType96® , Alere) détectant 333 gènes de virulence/résistance et assignant l’origine clonale de la souche. Résultats 61 souches de S. aureus ont été isolées (4 patients ayant 2 types de S. aureus de morphotypes différents). La prévalence des SARM était de 19,7 %. Treize complexes clonaux connus et 4 singletons ont été identifiés. Le clone ST398 (d’origine animale notamment porcine) était le plus fréquemment détecté (n = 20, 33 %) représentant 41 % des souches sensibles à la méticilline. Ces souches ont été isolées dans 10 hôpitaux sur 12. Aucun lien n’a pu être démontré entre les différents patients, suggérant une propagation nationale de ce clone. Ces souches ont la particularité d’être productrices de pénicillinase et sensibles aux autres antibiotiques. Conclusion Cette étude multicentrique montre pour la première fois l’émergence et la dissémination du clone ST398 dans les ostéites du pied diabétique en France. L’adaptation d’un clone passé de l’animal à l’homme est un problème alarmant nécessitant une surveillance accrue.
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In-situ forming poly(lactic-co-glycolic acid) (PLGA) implants offer a great potential for controlled drug delivery for a variety of applications, e.g. periodontitis treatment. The ...polymer is dissolved in a water-miscible solvent. The drug is dissolved or dispersed in this solution. Upon contact with aqueous body fluids, the solvent diffuses into the surrounding tissue and water penetrates into the formulation. Consequently, PLGA precipitates, trapping the drug. Often, N-methyl-2-pyrrolidine (NMP) is used as a water-miscible solvent. However, parenteral administration of NMP raises toxicity concerns. The aim of this study was to identify less toxic alternative solvent systems for in-situ forming PLGA implants. Various blends of polyethylene glycol 400 (PEG 400), triethyl citrate (TEC) and ethanol were used to prepare liquid formulations containing PLGA, ibuprofen (as an anti-inflammatory drug) and/or chlorhexidine dihydrochloride (as an antiseptic agent). Implant formation and drug release kinetics were monitored upon exposure to phosphate buffer pH 6.8 at 37 °C. Furthermore, the syringeability of the liquids, antimicrobial activity of the implants, and dynamic changes in the latter’s wet mass and pH of the release medium were studied. Importantly, 85:10:5 and 60:30:10 PEG 400:TEC:ethanol blends provided good syringeability and allowed for rapid implant formation. The latter controlled ibuprofen and chlorhexidine release over several weeks and assured efficient antimicrobial activity. Interestingly, fundamental differences were observed concerning the underlying release mechanisms of the two drugs: Ibuprofen was dissolved in the solvent mixtures and partially leached out together with the solvents during implant formation, resulting in relatively pronounced burst effects. In contrast, chlorhexidine dihydrochloride was dispersed in the liquids in the form of tiny particles, which were effectively trapped by precipitating PLGA during implant formation, leading to initial lag-phases for drug release.
Introduction L’ostéite du pied diabétique (OPD) nécessite dans 36% des cas une amputation. La méconnaissance de l’inoculum bactérien en présence ainsi que le développement d’un biofilm résistant aux ...antibiotiques sont des facteurs limitant la prise en charge. Le biofilm empêche la pénétration des antibiotiques et ralentit la croissance des bactéries. Seuls les biofilms développés par les staphylocoques sont bien identifiés au niveau des ulcères chroniques. Le but de cette étude est de caractériser l’atteinte bactérienne quantitative de l’OPD, sa composition exhaustive et sa capacité à produire un biofilm. Matériels et méthodes Il s’agit d’une étude prospective dans 2 centres sur 15 mois permettant le recueil de 38 biopsies osseuses (BO) par voie saine chez 35 patients avec ostéite métatarsienne prouvée radiologiquement. Par une technique de dilution, la charge bactérienne/g d’os a pu être définie sur 2 prélèvements non contigus avec identification des bactéries aéro et anaérobies. La capacité à produire un biofilm a été identifiée phénotypiquement par l’étude de la production de la matrice extra-cellulaire et l’adhérence à une structure inerte. Résultats La quantification bactérienne moyenne de l’ostéite est de 5 000 bactéries/g d’os. L’identification a permis la constitution d’une collection de 77 souches appartenant à 29 espèces bactériennes dont des staphylocoques coagulase négative, parfois pathogènes et pourtant souvent non communiqués. 65% des staphylocoques produisaient de l’exopolysaccharide (test au rouge congo), 76,6% présentaient des capacités d’adhérence (test au crystal violet) avec une concordance des 2 tests de 76%. Conclusion Ce travail a permis de mesurer pour la première fois la charge bactérienne de l’OPD répartie de façon homogène confirmant l’intérêt de la BO. Les staphylocoques présents au niveau de l’OPD sont capables en grande majorité de produire un biofilm. L’analyse de l’expression des différents gènes nous permettra de mieux connaître les mécanismes impliqués et pourrait ouvrir de nouvelles perspectives thérapeutiques.
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Several formulation strategies have been proposed for oral colon delivery, particularly for the therapy of inflammatory bowel disease (IBD). However, targeting the large intestine ...remains a challenging goal. The aim of this study was to develop and evaluate a novel type of drug delivery system, which is based on multiple drug release triggers for reliable performance. The system consists of: (i) a drug core, (ii) an inner swellable low-viscosity hydroxypropyl methylcellulose (HPMC) layer, and (iii) an outer film coating based on a Eudragit® S:high-methoxyl (HM) pectin (7:3 w/w) blend, optionally containing chitosan. Convex immediate release tablets (2 or 4 mm in diameter) containing paracetamol or 5-aminosalicylic acid (5-ASA) were coated in a fluid bed. The double-coated tablets exhibited pulsatile release profiles when changing the release medium from 0.1 N HCl to phosphate buffer pH 7.4. Also, drug release was faster in simulated colonic fluid (SCF) in the presence of fecal bacteria from IBD patients compared to control culture medium from tablets with outer Eudragit® S: HM pectin: chitosan coatings. The latter systems showed promising results in the control of the progression of colitis and alteration of the microbiota in a preliminary rat study.
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Different types of in-situ forming implants based on poly(lactic-co-glycolic acid) (PLGA) for the controlled dual release of an antiseptic drug (chlorhexidine) and an ...anti-inflammatory drug (ibuprofen) were prepared and thoroughly characterized in vitro. N-methyl-pyrrolidone (NMP) was used as water-miscible solvent, acetyltributyl citrate (ATBC) as plasticizer and hydroxypropyl methylcellulose (HPMC) was added to enhance the implants’ stickiness/bioadhesion upon formation within the periodontal pocket. Different drug forms exhibiting substantially different solubilities were used: chlorhexidine dihydrochloride and digluconate as well as ibuprofen free acid and lysinate. The initial drug loadings were varied from 1.5 to 16.1%. In vitro drug release, dynamic changes in the pH of the surrounding bulk fluid and in the systems’ wet mass as well as polymer degradation were monitored. Importantly, the release of both drugs, chlorhexidine and ibuprofen, could effectively be controlled simultaneously during several weeks. Interestingly, the tremendous differences in the drug forms’ solubilities (e.g., factor >5000) did not translate into major differences in the resulting release kinetics. In the case of ibuprofen, this can likely (at least in part) be attributed to significant drug-polymer interactions (ibuprofen acts as a plasticizer for PLGA). In the case of chlorhexidine, the release of the much less soluble dihydrochloride was even faster compared to the more soluble digluconate (when combined with ibuprofen free acid). In the case of ibuprofen, at higher initial drug loadings also limited solubility effects within the implants seem to play a role, in contrast to chlorhexidine. In the latter case, instead, increased system porosity effects likely dominate at higher drug loadings.
Over the past decades, increasing interests took place in the realm of drug delivery systems. Beyond treating intestinal diseases such as inflammatory bowel disease, colon targeting can provide ...possible applications for oral administration of proteins as well as vaccines due to the lower enzymatic activity in the distal part of GIT. To date, many strategies are employed to reach the colon. This article encompasses different biomaterials tested as film coatings and highlights appropriate formulations for colonic drug delivery. A comparison of different films was made to display the most interesting drug release profiles. These films contained ethylcellulose, as a thermoplastic polymer, blended with an aqueous shellac ammonium salt solution. Different blend ratios were selected as well for thin films as for coated mini-tablets, mainly varying as follows: (80:20); (75:25); (60:40). The impact of blend ratio and coating level was examined as well as the addition of natural polysaccharide “inulin” to target the colon.
In vitro
drug release was measured in 0.1 M HCl for 2 h followed by phosphate buffer saline pH 6.8 to simulate gastric and intestinal fluids, respectively. Coated mini-tablets were exposed to fresh fecal samples of humans in order to simulate roughly colonic content. Several formulations were able to fully protect theophylline as a model drug up to 8 h in the upper GIT, but allowing for prolonged release kinetics in the colon. These very interesting colonic release profiles were related to the amount of the natural polysaccharide added into the system.
Graphical Abstract
Polysaccharides were identified, which allow for colon targeting in human Inflammatory Bowel Disease (IBD) patients, as well as in rats and dogs (which are frequently used as animals in preclinical ...studies). The polysaccharides are degraded by colonic enzymes (secreted by bacteria), triggering the onset of drug release at the target site. It has to be pointed out that the microbiota in rats, dogs and humans substantially differ. Thus, the performance of this type of colon targeting system observed in animals might not be predictive for patients. The aim of this study was to limit this risk. Different polysaccharides were exposed to culture medium inoculated with fecal samples from IBD patients, healthy dogs and “IBD rats” (in which colonic inflammation was induced). Dynamic changes in the pH of the culture medium were used as an indicator for the proliferation of the bacteria and, thus, the potential of the polysaccharides to serve as their substrate. Fundamental differences were observed with respect to the extent of the pH variations as well as their species-dependency. The most promising polysaccharides were used to prepare polymeric film coatings surrounding 5-aminosaliciylic acid (5-ASA)-loaded starter cores. To limit premature polysaccharide dissolution/swelling in the upper gastro intestinal tract, ethylcellulose was also included in the film coatings. Drug release was monitored upon exposure to culture medium inoculated with fecal samples from IBD patients, healthy dogs and “IBD rats”. For reasons of comparison, also 5-ASA release in pure culture medium was measured. Most film coatings showed highly species-dependent drug release kinetics or limited colon targeting capacity. Interestingly, extracts from aloe vera and reishi (a mushroom) showed a promising potential for colon targeting in all species.
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Abundant data have incriminated intestinal bacteria in the initiation and amplification stages of inflammatory bowel diseases. However, the precise role of intestinal bacteria remains elusive. One ...theory has suggested a breakdown in the balance between putative species of “protective” versus “harmful” intestinal bacteria—this concept has been termed “dysbiosis”. Arguments in support of this concept are discussed.
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Diabetic foot infections are the most common complications requiring hospitalisation of patients with diabetes. They often result in amputation to extremities and are associated with ...high morbi-mortality rates, especially when bone is infected. Treatment of these complications is based on surgical procedures, nursing care and systemic antibiotic therapy for several weeks, with a significant risk of relapse. Due to low blood flow and damage caused by diabetic foot infection, blood supply is decreased, causing low antibiotic diffusion in the infected site and an increase of possible bacterial resistance, making this type of infection particularly difficult to treat. In this context, the aim of this work was to develop a medical device for local antibiotic release. The device is a lyophilized physical hydrogel, i.e a sponge based on two oppositely charged polyelectrolytes (chitosan and poly(cyclodextrin citrate)). Cyclodextrins, via inclusion complexes, increase drug bioavailability and allow an extended release. Using local release administration increases concentrations in the wound without risk of toxicity to the body and prevents the emergence of resistant bacteria. The hydrogel was characterised by rheology. After freeze-drying, a curing process was implemented. The swelling rate and cell viability were evaluated, and finally, the sponge was impregnated with a ciprofloxacin solution to evaluate its drug release profile and its antibacterial activity.
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